1. Field of the Invention
The present invention relates to a defibrillator system that reports the operational status of a defibrillator included in the system.
2. Description of the Prior Art
Electrotherapy devices are used to provide electric shocks to treat patients for a variety of heart arrhythmias. For example, external defibrillators typically provide relatively high-energy shocks to a patient (as compared to implantable defibrillators), usually through electrodes attached to the patient's torso. External defibrillators are used to convert ventricular fibrillation (“VF”) or shockable ventricular tachycardia (“VT”) to a normal sinus rhythm. Similarly, external cardioverters can be used to provide paced shocks to convert atrial fibrillation (“AF”) to a more normal heart rhythm.
Sudden cardiac arrest (“SCA”) is the leading cause of death in the United States. On average, 1000 people per day die; this translates into one death every two minutes. It is likely that these statistics would, at a minimum, hold true for third world countries. However, in view of difficulty in acquiring reliable data, statistics are not widely available.
Most sudden cardiac death is caused by VF, in which the heart's muscle fibers contract without coordination, thereby interrupting normal blood flow to the body. The only effective treatment for VF is electrical defibrillation, which applies an electrical shock to the patient's heart. The electrical shock clears the heart of the abnormal electrical activity (in a process called “defibrillation”) by depolarizing a critical mass of myocardial cells to allow spontaneous organized myocardial depolarization to resume.
To be effective, the defibrillation shock must be delivered to the patient within minutes of the onset of VF. Studies have shown that defibrillation shocks delivered within one minute after the onset of VF achieve up to a 100% survival rate. However, the survival rate falls to approximately 30% after only 6 minutes. Beyond 12 minutes, the survival rate approaches zero. Importantly, the more time that passes, the longer the brain is deprived of oxygen and the more likely that brain damage will result. As improved access to defibrillators increases, survival rates from SCA also increase.
Defibrillators must function when their use is required; no time or very little time exists for rehabilitating a non-functional defibrillator in an emergency situation. A defibrillator treats a condition that requires immediate treatment or death could result. If a defibrillator is not functional, within minutes a patient will almost certainly suffer severe permanent damage or die. Additionally, the nature of a defibrillator in that it includes electrical circuitry and a power supply contribute to the requirement that a defibrillator be functional. Unlike a mechanical device, which might be fixable in a short period of time, such is not typically possible for a defibrillator.
A recent trend has placed defibrillators in public places for use in emergency situations prior to arrival of emergency response personnel and in situations, such as on airborne aircraft where emergency response personnel are not available. Concerns regarding the associated with the functionality of a defibrillator rise in connection with such publicly placed defibrillators. Unlike a hospital or ambulance setting where a backup may be available, such a backup may not be available for publicly placed defibrillators.